Does gpu rendering support on gt 730 ddr3 or gt730v2 ddr5?
According to this page in the blender reference manual they claim that


  We support graphics cards starting from GTX 4xx (computing capability 2.0).


I also found both the cards you mentioned in the list of CUDA-enabled GeForce products on this NVIDIA page with computing capabilities listed as 2.1 and 3.5 so I would claim that yes, GPU-rendering does supports those cards, especially the ddr5-model.